Is a husband entitled to abandon his wife, commit sins, and get to know other women under the pretext that he is desirable?

Your husband is committing a grave sin by engaging in relationships with women online, looking at them, and speaking with them. This falls under the category of metaphorical zina (fornication/adultery). You must advise him and explain the truth to him, seeking assistance from Allah and righteous people. As for the husband, he must fear Allah, for his limbs will testify against him on the Day of Judgment. Allah Almighty says: "Indeed, the hearing, the sight, and the heart - about all those [one] will be questioned."